package org.apache.commons.graph.weight.primitive

import org.apache.commons.graph.weight.Monoid
import org.apache.commons.graph.weight.OrderedMonoid
import java.math.BigInteger

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

/**
 * The class [BigIntegerWeightBaseOperations] provides operations and properties
 * for weights of type [BigInteger].
 */
object BigIntegerWeightBaseOperations : OrderedMonoid<BigInteger> {
    /**
     * {@inheritDoc}
     */
    override fun append(s1: BigInteger, s2: BigInteger): BigInteger {
//        if (s1 == null || s2 == null) {
//            return null
//        }
        return s1.add(s2)
    }

    /**
     * {@inheritDoc}
     */
    override fun compare(o1: BigInteger, o2: BigInteger): Int {
        return o1.compareTo(o2)
    }

    /**
     * {@inheritDoc}
     */
    override fun identity(): BigInteger {
        return BigInteger.ZERO
    }

    /**
     * {@inheritDoc}
     */
    override fun inverse(element: BigInteger): BigInteger {
        return element.negate()
    }

}


val Monoid.Companion.bigInteger get() = BigIntegerWeightBaseOperations